/Engine/Source/Runtime/Analytics/Analytics/Public/Interfaces/IAnalyticsProvider.h
Starts a session. It's technically legal to send events without starting a session. The use case is for backends and dedicated servers to send events on behalf of a user without technically affecting the session length of the local player. Local players log in and start/end the session, but remote players simply call SetUserID and start sending events, which is legal and analytics providers should gracefully handle this. Repeated calls to this method will be ignored.
true if the session started successfully.
bool StartSession()